The woman’s stomach pain and back pain after intercourse may be due to the following causes: a. It may be caused by muscle fatigue here. In the process of intercourse, the muscles of the waist and abdomen will be used in large quantities, which may cause excessive muscle fatigue here, and then produce pain, which is more likely to occur in the case of a weak female body. Second, it may be due to soft tissue damage here. If the action during intercourse is too intense, it may cause the above-mentioned part of the muscle to produce sprain and contusion type of injury, and then lead to pain. Third, it may be due to a sterile inflammation here. For example, if you get cold during intercourse, it may cause a series of aseptic inflammation here, which may cause pain.